There should not be any panic for Arsenal, given this was their first defeat since August, and their first to a team not called Manchester City or Chelsea.

But defeat it was and to a side in real danger of relegation who, at times, have looked a hopeless cause. A brace from Danny Ings and a late clincher from Charlie Austin gave the crowd at St Mary's the unfamiliar feeling of hope.

Arsenal, unusually, looked complacent at times, with the loose sense that they expected another goal to arrive at some point. They equalised twice, on each occasion through Henrikh Mkhitaryan, but ran out of time to do so once more.

Southampton opened the scoring after 20 minutes when Matt Targett's perfect cross from the left found Ings in space amid Arsenal's makeshift defence to head home. The hosts deserved their lead, but lost it minutes later when Alex Iwobi and Nacho Monreal combined superbly down the left and Mkhitaryan used the pace of the Spanish international's cross to perfectly place home his third goal of the season.

Just before half-time, though, Ings scored again, with an effort similar to his first. The cross came from the right from Nathan Redmond, and the defender he stepped in front of was Stephan Lichtsteiner, but like when Laurent Koscielny lost track earlier, Ings took advantage. The world seemed to briefly pause as his header slowly looped through the air and into the net.

In one of the season's odder statistics, Arsenal still have not held the lead at half-time of a Premier League game, but they did draw level just after the break when Mkhitaryan's moderate effort took a colossal deflection off Jannik Vestergaard to wrong-foot goalkeeper Alex McCarthy.

Lucky as the Armenian international's sixth goal for Arsenal in 25 league games might have been, it does mean he already has more than the five he managed in 39 while with Manchester United.

Arsenal pushed forward but could not break through and with five minutes remaining were hit on the counterattack. Substitute Shane Long, who previously had a goal ruled out for offside, clipped a beautiful cross to the far post that Bernd Leno misjudged, allowing fellow replacement Charlie Austin to head into an empty net. He has played five times against Arsenal and scored in every game.

Arsenal lost in the Premier League for the first time since Aug. 18.

2. Defensive woes doom the Gunners

Arsenal face Tottenham in the Carabao Cup quarterfinal on Wednesday, and Unai Emery might have to ask around London Colney to see if there are any fit defenders who are up for playing. Recently retired Per Mertesacker, a spectator at St Mary's, might be wise to check if his boots still fit.

Arsenal started this game with a defence that, given injuries and suspensions, was always going to feature some improvisation. So it was that Emery's three central defenders were full-back Lichtsteiner, midfielder Granit Xhaka and Koscielny, who was probably back in league action earlier than he would have liked after missing seven months with a ruptured Achilles.

If that looked makeshift, it was reminiscent of the legendary Lee Dixon-Tony Adams-Steve Bould-Nigel Winterburn alignment, compared to how they finished the game. Lichtsteiner and Hector Bellerin were forced off with injuries, which add to Rob Holding's absence for the season, among other issues.

Emery has not had to deal with many problems in his nascent Arsenal tenure so far, but having to patch up his backline for the frantic festive period might be his biggest so far.

3. Southampton have hope

Under Mark Hughes, Southampton were, if not circling the drain of relegation, at least heading for significant trouble, so the surprise was perhaps not in his dismissal but that it did not come sooner. Ralph Hasenhuttl has only been in place for 10 days, but you can already see the difference.

His players look like all have a common purpose, for a start, pressing and harassing Arsenal's makeshift defence into mistakes with an intensity not seen in these parts for a while. Often that spilled into excessive aggression and fouls, a few of which Southampton were lucky to get away with, but at least they showed more energy than before.

Indirectly, Hasenhuttl was helped out by the man he's often compared to, Jurgen Klopp: Ings is on loan from Liverpool for the season and perhaps showed why his parent club did not wish to let him leave permanently.

Ings' career might always have "what if" associated with it. The natural goalscoring talent that persuaded Liverpool to sign him from Burnley in 2015 was evident with his two strikes on Sunday, but carried with them a reminder of how much more he could have done, were it not for serious injuries that more or less scuppered his time at Anfield.

He has six goals in 11 appearances for the Saints, quite a return for someone playing in a team that has struggled all season. Now, though, he is part of a squad that has gone from uninspiring to hopeful of survival in less than a fortnight under their new, energetic manager, who celebrated this win on the pitch at full-time.